KALAMAZOO, MI — If history is any lesson, Mike O'Brien has a Herculean effort ahead if he's to become the congressman for Michigan's 6th District.

Like many Democrats before him, O'Brien is challenging U.S. Rep. Fred Upton, the moderate Republican who voters have been sending to Congress for the past quarter century. First elected in 1986, Upton has since won reelection 12 times, with nothing less than a 15-point margin of victory. On average, he's beaten his Democratic challengers by 32 percentage points.

But the district isn't as Republican as Upton's margins of victory might suggest. The 6th District, which includes Kalamazoo, Berrien, Van Buren, St. Joseph, Cass and Allegan counties, is only about 54 percent Republican, said Bill Ballenger, editor of Inside Michigan Politics and a longtime political analyst.

"It's not beyond the realm of possibility that a Democrat can win it," Ballenger said in an interview with MLive/Kalamazoo Gazette following Upton's victory Tuesday in the GOP primary over conservative Republican Jack Hoogendyk.

But while the district is not solid GOP territory, Ballenger said Upton has a lock on the seat.

"As long as Upton is there, it's not going to be winnable for the Democrats," said Ballenger, citing the congressman's longevity, ability to raise millions of dollars and his overall popularity in the district.

But O'Brien, making his first run for elective office on Nov. 6, is challenging Upton's appeal, saying the St. Joseph Republican's politics have turned more to the right and that represents the special interests which have, so far, donated $2 million to his reelection campaign.

And for many local party members, the idea of a Democrat beating Upton is beyond the realm of possibility.

Joe Haas, a Sturgis attorney who chairs the 6th District Republicans, said a Democrat could win in the region, but it would be nearly impossible at this stage since Upton has attracted so many independent voters.

"It would take an awful special candidate to pull that off and take a Republican candidate that is much different than Fred Upton," Haas said.

What will it take to win

Local Democrats know their district isn't as red as maps make it out to be.

"We know that a Democrat has won in Southwest Michigan: Barack Obama. Before him, Bill Clinton. Twice," Mark Miller, the 6th District's Democratic chairman, wrote in an e-mail. "So we know for a fact that many, many voters split their ticket to vote for them and Upton in the same election."

Since taking the chairmanship of the House Energy and Commerce Committee, Upton has become more prominent in his party, and a more vocal critic of Obama. Upton has been criticized by the left for his environmental policies in recent years.

"What it will take is a realization on the part of those Democrats in the district who have routinely voted for Upton, and independent voters, that he is no longer the moderate who was a good fit for the district for so many years," Miller said.

Republicans like Haas, however, say Upton has not shifted to the right.

"There is a significant liberal agenda coming out of the Senate and White House," he said in arguing that Upton has not become more conservative in his positions.

To beat Upton, Ballenger said a Democratic candidate would need name recognition, a positive reputation and money.

And if the race becomes competitive in September or October, interest groups could kick in money, he added. To win, he said, the challenger would have to spend more money than the incumbent.

But if Upton felt threatened by a Democrat in a general election, the national Republican Party would come in and help, Ballenger added. "Upton would raise and spend more money than you ever dreamed possible."

So far this election cycle, Upton has raised more than $3 million and has spent $2 million. In three months before the most recent primary against Hoogendyk, Upton spent $1 million.

Miller said O'Brien, who did not face a primary challenge, will "need enough money to get his message out, but nowhere near as much as Fred has."

For Don Cooney, raising money was the hardest part of the two times he ran against Upton.

"You can't match Fred with money," said Cooney, who ran for Congress as a Democrat in both 2008 and 2010. "The only way to match him is with people."

Upton got 59 percent of the vote in beating Cooney in 2008 and stretched that to 65 percent in 2010. Cooney raised $82,000 in 2008 and $62,000 in 2010, compared to $1.4 million and $2 million, respectively, for Upton in those years. So far, O'Brien has raised more than $100,000.

In addition to the money gap, Cooney said the district is difficult for a Democrat.

"Really, it's murder," the Kalamazoo city commissioner said. "The first time, the strategy was to have a chance in Kalamazoo, Benton Harbor and Niles. And we did, but we couldn't overcome the rest of the district."

While Kalamazoo and Benton Harbor both voted heavily Democratic, the campaign tried, but failed, to build momentum in areas like Paw Paw and Lawrence. And, Cooney said, Democrats in St. Joseph — Upton's hometown — were not interested in his campaign.

"They are so Republican," he said. "The district is really in Fred's favor."

O'Brien's shot

In his many re-elections, Upton has clearly excelled at winning votes from independents and moderates. And so far, those are the voters who O'Brien said represent the greatest opportunity for him.

"We really are hearing from people in the district who classify themselves as Republicans ... Libertarians who are looking for a change," said O'Brien. These people, he said, are writing checks and introducing the candidate to their friends, he said.

O'Brien, 48, is a project manager at Herman Miller and a former Marine making his first run at political office.

The Douglas resident said what makes his campaign different from previous challenges to Upton by a Democrat is that he is running a more professional campaign: he has an office, a staff and O'Brien said he plans on working full-time on the campaign in the next few weeks.

While O'Brien may not have their vote, or cause them panic, some local Republicans said he is the best candidate they've seen from the Democrats in the 6th District.

Gene Clem, president of the Southwest Michigan Tea Party Patriots, said he has been telling the Democrats every year to run a different candidate.

"You have a chance if you pull out a good, conservative Democrat," Clem said. "If you keep putting in left-wing people, you don't have a chance."

And O'Brien looks like he could be such a candidate, Clem said. "From what I know about him ... he's the strongest the Democrats have put up in this district in while."

Hass, too, was impressed by the choice of O'Brien.

"He's the type of candidate that can be more attractive, more than a Don Cooney," Clem said of the social-work professor at Western Michigan University. "I think Democrats have finally recognized that in trying to pick a candidate."

While many of the positions and opinions held by O'Brien and Upton will be debated during the election, both candidates want to appeal to voters beyond their base.

"My service, my farming, my business experience will relate to a lot of what's going through the lives of people in the district," O'Brien said.

On primary election night, Upton repeated something he said during the campaign against Hoogendyk: Voters in the 6th District don't care if a politician has a 'D' or 'R' after his name, they care whether he gets things done.